This invention relates to a method of controlling the molecular weight of polycarbonates prepared by the interfacial technique by adding ammonia or ammonium compounds to the reaction media.
It is known from U.S. Pat. No. 3,028,365 that in the interfacial polymerization process to make aromatic polycarbonates from dihydric phenols and phosgene the use of small amounts of monohydric phenols will control the molecular weight of the polycarbonates.
It is further known from Ser. No. 661,672 filed Feb. 26, 1976 that small amounts of metallic sulfites are effective to control the molecular weight of polycarbonates during their formation.